How severe is CVE-2021-44856?

CVE-2021-44856 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.

Is CVE-2021-44856 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-44856?

CVE-2021-44856 primarily affects Mediawiki. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-44856?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-44856 published?

CVE-2021-44856 was published on 2022-12-26 and last updated on 2026-06-17.

CVE-2021-44856

CVE-2021-44856 is a medium-severity vulnerability in Mediawiki with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-754.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
EPSS exploit prediction: 0% (39th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-754
Affected product: Mediawiki
Published: 2022-12-26
Last modified: 2026-06-17

Description

An issue was discovered in MediaWiki before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1. A title blocked by AbuseFilter can be created via Special:ChangeContentModel due to the mishandling of the EditFilterMergedContent hook return value.

Frequently asked questions

What is CVE-2021-44856?: An issue was discovered in MediaWiki before 1.35.5, 1.36.x before 1.36.3, and 1.37.x before 1.37.1. A title blocked by AbuseFilter can be created via Special:ChangeContentModel due to the mishandling of the EditFilterMergedContent hook return value.
How severe is CVE-2021-44856?: CVE-2021-44856 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity low, and availability none.
Is CVE-2021-44856 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (39th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-44856?: CVE-2021-44856 primarily affects Mediawiki. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-44856?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-44856 published?: CVE-2021-44856 was published on 2022-12-26 and last updated on 2026-06-17.

References

Affected products (5)

cpe:2.3:a:mediawiki:mediawiki:*:*:*:*:*:*:*:*
cpe:2.3:a:mediawiki:mediawiki:1.37.0:-:*:*:*:*:*:*
cpe:2.3:a:mediawiki:mediawiki:1.37.0:rc0:*:*:*:*:*:*
cpe:2.3:a:mediawiki:mediawiki:1.37.0:rc1:*:*:*:*:*:*
cpe:2.3:a:mediawiki:mediawiki:1.37.0:rc2:*:*:*:*:*:*

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